Tag Archives: science

The Science of Fireworks

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We all know the history of Bonfire Night, but do you know the science?

The Explosion

All fireworks are essentially a combustion reaction, like fire, that produces light and heat.

Fireworks tend to have a long fuse that burns slowly so you have time to light the fuse and run away before the big bang! The fuse first reaches a compartment containing gunpowder, it ignites this causing the firework to launch into the night. There is a delayed fuse to ignite the next explosion, this heats the “stars”.

The stars in a firework are individual compartments containing a different composition of chemicals, depending on the desired colour and effect of the firework. The stars may even be arranged inside the shell of the firework so that they burst in a certain formation to form a shape.

The Colours

Firework displays always use a range of striking colours, the variety of colours comes from the use of different chemicals. Elements such as barium, copper and lithium burn with a coloured flame and are chosen for use in fireworks due to the bright colours they produce.

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The Sound

When the chemicals inside the firework’s shell are heated they convert from a solid to a gas. The gas takes up more space than there is available inside the shell so it bursts out creating a loud BANG.

Crackling noises come from fireworks which contain lead. When lead oxide is heated and vapourised, the vapour atoms produce crackling noises.

The whistling sound that you hear when the fireworks shoot up in the air, comes from the firework tube itself, not the chemicals. When the tube is partly empty, it will vibrate the air passing through it, causing a whistle.

How can you write your name with a sparkler?

I’m sure you’ve all held a lit sparkler at some point and twirled it around in the air to see a trail of light lingering in the air for a few seconds. The truth is the light isn’t really still there but your eyes play a trick on your brain to make you think that it is. Image resultOur eyes don’t react as quickly as you might think when our view changes, they usually keep the old view around for a fraction of a second. This is known as visual persistence and it’s what allows us to view a series of still images as movement. The effect is increased in the case of the sparklers due to the very bright light emitted form the sparks contrasting against the dark background. This makes the light appear to last longer.

 

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#TryThisTuesday: Honeycomb

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Honeycomb or Cinder Toffee not only makes a great Bonfire Night snack, it’s also a fun and quick science experiment! Here’s our simple recipe for the honeycomb reaction:
1. Grease a baking tray with butter and set aside.
2. Mix 100g sugar with 2.5 tablespoons of golden syrup in a pan. Mix the two well before you heat the pan.


3. Gently heat the pan, try not to stir the mixture at this point just let it gently begin to melt.
4. Once you can see the sugar start to melt you can push the sugar around to ensure in melts evenly and doesn’t burn.
5. When all the sugar has melted turn up the heat so the sugar begins to boil and forms an amber coloured caramel
6. Turn off the heat and add one teaspoon of bicarbonate of soda, beat the mixture quickly as it begins to bubble up to incorporated all the bicarb then tip onto the greased baking tray.


7. Leave to set for 30-60 minutes then enjoy!

The Science

The heat causes the bicarbonate of soda (NaHCO3) to break down and release the gas, carbon dioxide (CO2). The gas gets trapped within the sugar, this results in the bubbles in your honeycomb.

honeycomb

Black History Month: 6 Influential Black Scientists

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To honour Black History Month, we’ve taken a look at some notable black scientists and what they have achieved in their scientific fields.

1. Benjamin Banneker (1731-1806)

The son of a former slave, Benjamin was born in Maryland, USA. In 1753, he produced the first working clock in America, it struck every hour on the hour. Benjamin was also a keen astronomer and worked on calculating lunar and solar eclipses.

2. Ernest Everett Just (1883-1941)

Raised by his mother in South Carolina, USA, Ernest grew up to become an influential biologist. He argued that cells should be studied as a whole under normal conditions, rather than breaking them up and subjecting them to unnatural lab conditions.

3. Percy Lavon Julian (1899-1975)

Percy was born in Alabama and went on to study at Harvard University and the University of Vienna in Austria. Percy was an American chemist who focused on researching the chemical synthesis of medicinal drugs from plants. His work paved the way for the mass production of contraceptive pills and he also worked on large scale synthesis of human hormones, such as testosterone.

 

4. Charles Richard Drew (1904-1950)

Charles was the first African American to earn a Doctor of Medical Science degree. During World War II, Charles worked on a revolutionary project called Blood for Britain, he created trucks that stored refrigerated blood that could be transported to soldiers in need. He also set up blood donation centers and ensured all blood was tested and handled correctly. Charles’ work led to the American Red Cross Blood Bank and undoubtedly saved thousands of lives.

5. Maggie Aderin-Pocock (1968)


Born to Nigerian parents, Maggie grew up in London with dyslexia and the ambition of becoming an astronaut. Despite discouraging teachers, she went on to earn a BSc in Physics and a doctorate in Mechanical Engineering from Imperial College London. Maggie worked on a project to probe the centre of stars billions of miles away. Maggie is passionate about inspiring young children to pursue careers in science and has presented various BBC science documentaries.

 

6. Mae Jemison (1956)

Mae was the first African American woman to travel in space. She is a keen advocate of science education with a particularly interest in getting more minority students to go into science. Through her own company, the Jemison Group, Mae runs a science camp for children aged 12-16.

 

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9 Scientific Mistakes in Disney and Pixar

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Sorry to crush your dreams but we have inspected some of our favourite Disney films and some things just don’t sit right in our scientific minds. Here are nine examples of what would really happen, according to science. But remember anything is possible in the world of Disney…

1. Finding Nemo

All clown fish are born male. Each group of clown fish has one female, the biggest fish. When the female dies, the biggest male fish will become female, this is know as being a sequential hermaphrodite.  When Nemo’s mother was killed by the barracuda, Marlin would have become female, leaving Nemo as the dominant male.

finding-nemo

2. The Lion King

Rafiki is introduced to us in the Lion King, where he performs Simba’s birth ceremony. He also sings a song in the film “Asante sana, squash banana, wewe nugu, mimi hapana”. This is a Swahili rhyme which translates to “Thank you very much (squash banana), you’re a baboon and I’m not!”. Rafiki doesn’t belong to any species, he is a cross between a mandrill and a baboon, he has the colourful nose and cheeks of a mandrill and the mane and long tail of a baboon.

3. Up

In the film Up, Carl ties thousands of balloons to his house to go on an adventure to South America. However, the number of balloons he uses are not enough to lift a house. Estimating that the house weighs 45,000 kg, you would need over 3 million balloons!

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4. Inside Out

Inside Out personifies five major emotions; Joy, Sadness, Fear, Anger and Disgust which all work together to guide and protect their human (Riley). However, there are actually six core emotions, with Disney missing out surprise. These six emotions are found to be universally recognized and expressed across the world, even in remote tribes that would not have learned the meaning of such facial expressions elsewhere.

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5. Tarzan

After baby Tarzan was left alone in the jungle to be raised by gorillas, he eventually grows up and meets Jane who teaches him to speak English. Unfortunately in the real world, no matter how great a teacher Jane was, Tarzan would never have been able to talk. Scientists have described a critical period up to the age of 5 which is vital for language development. If children, like Tarzan, aren’t exposed to a human language in this time they will be unable to learn to speak later in life.

tarzan

6. Aladdin

Aladdin and Jasmine travel from Cairo (Egypt) to Athens (Greece) in one second on the magic carpet, meaning they would have to travel at 621 miles per second! The air resistance would be 100 million times larger than their weight, causing them to burn up, like when meteors burn up when they enter our atmosphere.

aladdin-1992

7. Star Wars

Star Wars is well know for its fights in space, full of explosions, blaster and engine sounds. However, space is a vacuum, meaning that it is devoid of matter, there are no gases or air there. Sound can’t travel in a vacuum, as sound vibrations don’t work, therefore we shouldn’t be able to hear any sound.

star wars

8. The Good Dinosaur

In the good dinosaur, a young dinosaur by the name of Arlo befriends a human boy. Arlo is an Apatosaurus which lived around 151 million years ago. Human beings as we are or Homo sapiens only evolved between 200,000 to 100,000 years ago so in reality Arlo and his friend would have missed each other by quite a few million years.

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9. Finding Dory

When searching for Dory’s family in Finding Dory, we discover that Dory was born in captivity, in an aquarium. However, Dory is a species of fish known as the Blue Tang. This species can’t be bred in captivity and have to be caught from their wild home of coral reefs in the Indo-Pacific Sea.

dory

 

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#TryThisTuesday: Balloon Kebab

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Your challenge this week is to pierce a skewer through a balloon without popping it.

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Share your attempts with us on Facebook, Instagram or Twitter  – just use the hashtag #TryThisTuesday

How we did it:


Pierce the balloon at the bottom near the knot, then slowly pass the skewer through and piece it through the darkest part at the far end. These points are where the rubber is under the least stress so is less likely to tear and pop under impact.

Did you manage it?